RedundantUnitExpressionInspection: support lambdas

#KT-39772 Fixed

idea/testData/inspectionsLocal/redundantUnitExpression/atLastAfterFunInIf.kt

@@ -1,4 +1,3 @@
-// PROBLEM: none
 fun test(b: Boolean): Unit = if (b) {
     fun a() = 1
     <caret>Unit

idea/testData/inspectionsLocal/redundantUnitExpression/atLastAfterFunInIf.kt.after

@@ -0,0 +1,4 @@
+fun test(b: Boolean): Unit = if (b) {
+    fun a() = 1
+} else {
+}

idea/testData/inspectionsLocal/redundantUnitExpression/atLastAfterFunInWhen.kt

@@ -1,4 +1,3 @@
-// PROBLEM: none
 fun test(b: Boolean): Unit = when (b) {
     true -> {
         fun a() {}

idea/testData/inspectionsLocal/redundantUnitExpression/atLastAfterFunInWhen.kt.after

@@ -0,0 +1,7 @@
+fun test(b: Boolean): Unit = when (b) {
+    true -> {
+        fun a() {}
+    }
+    else -> {
+    }
+}

idea/testData/inspectionsLocal/redundantUnitExpression/notRedundant4.kt

@@ -0,0 +1,28 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun nonUnit(p: Int): Int = p
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+    println(1)
+    nonUnit(2)
+
+    p?.let {
+        println(3)
+        nonUnit(4)
+        Unit<caret>
+    }
+}
+
+fun h() {
+    println(5)
+    nonUnit(6)
+}
+
+fun x() = doIt {
+    println(7)
+    nonUnit(8)
+    Unit
+}
+

idea/testData/inspectionsLocal/redundantUnitExpression/notRedundant5.kt

@@ -0,0 +1,28 @@
+// PROBLEM: none
+// WITH_RUNTIME
+fun nonUnit(p: Int): Int = p
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+    println(1)
+    nonUnit(2)
+
+    p?.let {
+        println(3)
+        nonUnit(4)
+        Unit
+    }
+}
+
+fun h() {
+    println(5)
+    nonUnit(6)
+}
+
+fun x() = doIt {
+    println(7)
+    nonUnit(8)
+    Unit<caret>
+}
+

idea/testData/inspectionsLocal/redundantUnitExpression/notRedundant6.kt

@@ -0,0 +1,16 @@
+// PROBLEM: none
+
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        null?.doDo()
+        Unit<caret>
+    }
+}
+

idea/testData/inspectionsLocal/redundantUnitExpression/notRedundant7.kt

@@ -0,0 +1,17 @@
+// PROBLEM: none
+// WITH_RUNTIME
+
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        1.let { it.let { it.let { it.let { null?.doDo() } } } }
+        Unit<caret>
+    }
+}
+

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType.kt

@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+
+    p?.let { Unit<caret> }
+}
+
+fun h() = Unit
+
+fun x() = doIt { Unit }

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType.kt.after

@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+
+    p?.let { <caret>}
+}
+
+fun h() = Unit
+
+fun x() = doIt { Unit }

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType2.kt

@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+
+    p?.let { Unit }
+}
+
+fun h() = Unit
+
+fun x() = doIt { Unit<caret> }

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType2.kt.after

@@ -0,0 +1,12 @@
+// WITH_RUNTIME
+
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun g(p: String?) {
+
+    p?.let { Unit }
+}
+
+fun h() = Unit
+
+fun x() = doIt { <caret>}

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType3.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+// PROBLEM: none
+// not yet supported
+fun <T> doIt(p: () -> T): T = TODO()
+
+fun x() = doIt<Unit> {
+    4
+    Unit<caret>
+}

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType4.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        1.let { it.let { it.let { it.let { it.doDo() } } } }
+        Unit<caret>
+    }
+}

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType4.kt.after

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        1.let { it.let { it.let { it.let { it.doDo() } } } }
+    }
+}

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType5.kt

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        1.let { it.let { it.let { it.let { it?.doDo() } } } }
+        Unit<caret>
+    }
+}
+

idea/testData/inspectionsLocal/redundantUnitExpression/unitReturnType5.kt.after

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+fun <T> doIt(p: () -> T): T = p()
+fun Any.doDo() = Unit
+
+abstract class A {
+    abstract fun a()
+}
+
+class B : A() {
+    override fun a() = doIt {
+        1.let { it.let { it.let { it.let { it?.doDo() } } } }
+    }
+}
+